The present invention relates to speed increasing devices and, more particularly, to speed increasing devices for use with powered multi-purpose woodworking tools.
Multi-purpose woodworking tools typically include a frame, a pair of parallel way tubes extending along a longitudinal dimension of the frame, and a head stock mounted for slidable adjustment on the way tubes. The head stock includes a motor and power transmission system having an output spindle. The output spindle of the head stock may drive various woodworking tools such as shapers, lathes, table saws, disk sanders, jointers, band saws and the like, which are mounted on the way tubes.
An example of a typical mu ti-purpose woodworking tool is shown in U.S. Pat. No. 3,282,309 to Parker et al in which a variety of woodworking tools may be powered directly by the output spindle of the head stock of the machine. The head stock is typically provided with means for varying the speed of the output spindle to accommodate the requirements of the particular tool being used. Thus, a lower spindle speed may be used for operations such as lathe turning while a higher spindle speed is required for operations such as those performed by shaping tools. While such an arrangement is acceptable for many woodworking operations, the highest spindle speed available is often too low to perform shaping operations quickly and efficiently.
Further, when using a typical multi-purpose woodworking tool as a shaper, the head stock must be rotated to a vertical position over a worktable for supporting the workpiece, which may reduce the operator's ability to view the work area as well as the accessibility to the work area in certain applications.
Consequently, there is a need for a speed increasing device which may be attached to an existing powered woodworking tool having a head stock mounted on a pair of parallel way tubes and which is capable of driving a rotating shaping tool at a rotational speed substantially higher than that of the spindle of the multi-purpose woodworking tool.
In addition, a speed increasing device is needed which is compact enough to be supported by the way bars of a multi-purpose woodworking tool having a horizontal output spindle and which provides an output shaft oriented perpendicularly to the output spindle of the woodworking tool such that the output shaft may be used to support the bit of a shaping tool protruding through a top surface of a work support table.